Hoisting apparatus, more particularly for use in a furnace

ABSTRACT

The invention relates to a hoisting apparatus having a yoke, at least two clamping members which are disposed on the end portions of the yoke, and can be moved towards and away from one another, means for driving and controlling the clamping members, and members for moving the yoke, in which the clamping members make only a very small displacement when they move from the clamping position into the release position, whereby at least one of the clamping members is so guided that it is displaced parallel with itself during the movement of the clamping members in relation to one another.

United States Patent 1191 Siegmund 1 March 6, 1973 HOISTING APPARATUS, MORE 796,842 8/1905 Hoffmann ..2l4/658 PARTICULARLY FOR USE IN A 2,224,913 12/1940 Johnson ..294/l ll X FURNACE FOREIGN PATENTS OR APPLICATIONS [75] Inventor: Frederik Willem Siegmund,

Bmhoven Netherlands 52,107 12/1966 Poland ..294/l06 1 Assigneel Nedel'landse Kraanbouw j's Primary ExaminerGerald M. Forlenza Utrecht Netherlands Assistant ExaminerGeorge F. Abraham 1221 Filed: Dec.28, 1970 Arwmeysnyder & Bulwm [21] Appl. No.: 101,994 [57] ABSTRACT The invention relates to a hoisting apparatus having a [30] Forelgn Apphcauon Pnority Data yoke, at least two clamping members which are Jan. 20, 1970 Netherlands ..7000804 disposed on the end portions of the yoke, and can be moved towards 'and away from one another, means for [52] U.S.C|. ..2l4/658, 294/62, 294/l1l driving and controlling the clamping members, and [51] Int. Cl. ..B66c 1/42 members for moving the yoke, in which the clamping ld of Search...2l4/1 BC, 1 BB, 658; 294/106, embers make only a very small displacement when 294/1 1 1, 62 they move from the clamping position into the release position, whereby at least one of the clamping mem- [56] References C'ted hers is so guided that it is displaced parallel with itself UNITED STATES PATENTS during the movement of the clamping members in relat1on to one another. 1,519,325 12/1964 Owen ..294/l06 3,139,302 6/1964 Orloff ..294/l06 X 6 Claims, 2 Drawing Figures 1" ,1 1 '1' I] 6 1 13 I I L5 9, ,4 .'1 l 11 F 17 16 ,1 H :1 .aT-f H L 14 1: Q 11 i o a] e o A l l wl Ej W i8 is 2 20 25 1 l I I V HOISTING APPARATUS, MORE PARTICULARLY FOR USE IN A FURNACE The invention relates to a hoisting apparatus having a yoke, at least two clamping members which are disposed on the end portions of the yoke and can be moved towards and away from one another, means for driving and controlling the clamping members, and members for moving the yoke.

In a hoisting apparatus of the kind specified the load to be hoisted is clamped laterally and then displaced. The load can consist of one or more elements. If a number of elements must be displaced simultaneously, the elements are so forced against one another by the exertion of an adequate force on the outermost elements that frictional forces therebetween are greater than the downwardly directed forces generated by the weight of the elements. As a rule the shape of the clamping members is adapted to that of the side surfaces of the elements to be clamped by the clamping members. When the elements are disposed in a laterally limited space, as, for instance, anode blocks for aluminum production in a furnace, there is the difficulty that the clamping members can make only a slight displacing movement from the clamping position to the release position.

With the prior art hoisting apparatuses the displacement of the clamping members between the clamping and release positions is so large that when they are used in a channel-shaped furnace, the furnace cannot be completely satisfactorily filled.

It is an object of the invention to provide a hoisting apparatus in which the clamping members make only a very small displacement when they move from the clamping position into the the release position. In taking steps to achieve this aim, care must be taken that in one possible application, i.e., in a furnace no means can be used which are incapable of standing up to elevated temperatures.

To this end the invention provides a hoisting apparatus of the kind specified wherein during their movement in relation to one another at least one of the clamping members is so guided that it is displaced parallel with itself. Since at least one of the clamping members is displaced parallel with itself, very little displacement is needed for movement from the clamping position into the release position, in contrast with clamping members which can pivot between such positions around a point at their ends.

In one advantageous embodiment of the invention the clamping member is moved via the agency of a lever which can be pivoted in relation to the yoke and moved between two end positions by the control means. Exclusively mechanical means are used to operate the clamping members, more particularly the part moving in the furnace. The clamping force of the clamping members is derived from a force generated by the lever. A weight can be disposed on the end of the lever to obtain an adequate force.

An embodiment of the invention will now be described in greater detail with reference to the drawings.

FIG. 1 is a partly sectional view of a hoisting apparatus according to the invention, and

FIG. 2 is a plan view, to an enlarged scale, of the hoisting apparatus shown in FIG. 1.

A hoisting apparatus 1 has a substantially horizontal yoke 2 on whose ends clamping members 3, 4 are disposed. The yoke 2 is disposed on the lower end of the innermost tube 5 of a set of telescopic tubes 5 7. A winch drum 9 driven by a motor 8 can move the tubes 5, 6 and therefore the yoke 2 up and down by means of a cable 11 running around a pulley 10. Control means for the clamping members, in the form of a pneumatic cylinder 12, are disposed inside the tube 5. Connected to the piston rod of the pneumatic cylinder 12 is a cable 13 whose end is attached to a lever 14 movable between two end positions. The end positions are determined by a stop 15 on the yoke 2 and a stop 16 on the tube 5 respectively. A lever 14 can move in a slot in the tube 5. A weight 17 is disposed on the end of the lever.

The clamping members 3, 4 are connected to the yoke 2 via the agency of strips 18, 19; 20, 21 disposed on the yoke 2 and the clamping members 3 and 4 respectively. The end of the strip 20 forms the pivot of the lever 14. Connected to bent end 22 of the lever is a connecting member 23 of adjustable length connected at its other end to the strip 19.

The apparatus operates as follows. To receive a load, e.g., a number of blockshaped elements 24 26, the yoke 2 is lowered until the clamping members 3, 4 are on either side of the elements placed ready. The lever 14 is in its top end position. A downward stroke of the piston in the cylinder 12, due to the weight 17, then moves the lever into its bottom position. The lowest pivoting point of the lever 14 moves to the right, as viewed in the drawing, while the bent end 22 moves to the left. The clamping member 4 consequently moves to the left in relation to the yoke 2, while the clamping member 3 moves to the right. The clamping force is derived from the force generated by the weight 17 and the lever arm. The clamping effect is therefore exerted in the bottom position of the lever, so that if the controlling means happen to fail, the load cannot drop out of the apparatus, this being a very important safety factor.

Clearly, in the construction according to the invention the clamping members 3, 4 are displaced parallel with themselves, so that the apparatus can be used in a space which is very limited laterally.

Lastly, the hoisting apparatus can be guided over, for instance, rails. It can also be suspended from a crane or disposed vertically in some other way.

What I claim is:

1. A hoisting apparatus comprising, in combination:

a yoke in the form of an elongate, horizontal member of selected length;

a pair of clamp members disposed at the respective opposite ends of said yoke and each having a portion depending below said yoke for engaging against the opposite ends of a load in straddling relation thereto;

parallelogram link means suspending at least one of said clamp members from said yoke for movement toward and away from the other clamp member;

generally horizontal lever means overlying said yoke and connected at one end to said parallelogram link means for normally urging said one clamp member toward the other to effect a constant clamping force solely by reason of the weight of said lever means;

elevating means connected to said yoke for raising and lowering said yoke without affecting the clamping force exerted by said clamp members as effected by said lever means; and means for selectively pivoting said lever means upwardly to move said one clamp member away from the other whereby to release a load.

2. A hoisting apparatus as defined in claim 1 including second parallelogram link means suspending said other clamp member from said yoke, and a connecting member connected to said one end of said lever means and to said second parallelogram link means to operate said other clamp member in unison with, but in opposite sense to, said one clamp member. i

3. A hoisting apparatus as defined in claim 1 wherein said elevating means comprises a series of telescopic members, the lowermost of which is fixed to said yoke, and said means for selectively pivoting said lever means comprises an operating member located remotely above said yoke and a flexible member extending between and connected to said operating member and said lever means.

4. A hoisting apparatus as defined in claim 1 wherein said means for elevating comprises a series of telescopic members, the innermost of which is hollow and is connected at its lower end to said yoke, and said means for selectively pivoting said lever means comprises an operating member located in the upper portion of said innermost telescopic member remote from said yoke and a flexible member connected at one end to said operating member and projecting downwardly through said innermost telescopic member into connection with said lever means.

5. A hoisting apparatus as defined in claim 2 wherein said elevating means comprises a series of telescopic members, the lowermost of which is fixed to said yoke, and said means for selectively pivoting said lever means comprises an operating member located remotely above said yoke and a flexible member extending between and connected to said operating member and said lever means.

6. A hoisting apparatus as defined in claim 2 wherein said means for elevating comprises a series of telescopic members, the innermost of which is hollow and is connected at its lower end to said yoke, and said means for selectively pivoting said lever means comprises an operating member located in the upper portion of said innermost telescopic member remote from said yoke and a flexible member connected at one end to said operating member and projecting downwardly through said innermost telescopic member into connection with said lever means. 

1. A hoisting apparatus comprising, in combination: a yoke in the form of an elongate, horizontal member of selected length; a pair of clamp members disposed at the respective opposite ends of said yoke and each having a portion depending below said yoke for engaging against the opposite ends of a load in straddling relation thereto; parallelogram link means suspending at least one of said clamp members from said yoke for movement toward and away from the other clamp member; generally horizontal lever means overlying said yoke and connected at one end to said parallelogram link means for normally urging said one clamp member toward the other to effect a constant clamping force solely by reason of the weight of said lever means; elevating means connected to said yoke for raising and lowering said yoke without affecting the clamping force exerted by said clamp members as effected by said lever means; and means for selectively pivoting said lever means upwardly to move said one clamp member away from the other whereby to release a load.
 1. A hoisting apparatus comprising, in combination: a yoke in the form of an elongate, horizontal member of selected length; a pair of clamp members disposed at the respective opposite ends of said yoke and each having a portion depending below said yoke for engaging against the opposite ends of a load in straddling relation thereto; parallelogram link means suspending at least one of said clamp members from said yoke for movement toward and away from the other clamp member; generally horizontal lever means overlying said yoke and connected at one end to said parallelogram link means for normally urging said one clamp member toward the other to effect a constant clamping force solely by reason of the weight of said lever means; elevating means connected to said yoke for raising and lowering said yoke without affecting the clamping force exerted by said clamp members as effected by said lever means; and means for selectively pivoting said lever means upwardly to move said one clamp member away from the other whereby to release a load.
 2. A hoisting apparatus as defined in claim 1 including second parallelogram link means suspendiNg said other clamp member from said yoke, and a connecting member connected to said one end of said lever means and to said second parallelogram link means to operate said other clamp member in unison with, but in opposite sense to, said one clamp member.
 3. A hoisting apparatus as defined in claim 1 wherein said elevating means comprises a series of telescopic members, the lowermost of which is fixed to said yoke, and said means for selectively pivoting said lever means comprises an operating member located remotely above said yoke and a flexible member extending between and connected to said operating member and said lever means.
 4. A hoisting apparatus as defined in claim 1 wherein said means for elevating comprises a series of telescopic members, the innermost of which is hollow and is connected at its lower end to said yoke, and said means for selectively pivoting said lever means comprises an operating member located in the upper portion of said innermost telescopic member remote from said yoke and a flexible member connected at one end to said operating member and projecting downwardly through said innermost telescopic member into connection with said lever means.
 5. A hoisting apparatus as defined in claim 2 wherein said elevating means comprises a series of telescopic members, the lowermost of which is fixed to said yoke, and said means for selectively pivoting said lever means comprises an operating member located remotely above said yoke and a flexible member extending between and connected to said operating member and said lever means. 